The present invention generally relates to the processing of yarns, in particular, the present invention relates to spun filament or fiber yarns processed through a needling process to interlock or link the yarn filaments or fibers together.
In yarn manufacturing, yarns generally are spun from one or more fibers, including natural and/or synthetic fibers, using conventional ring, open-end, air-jet, worsted, woolen, or Dref spinning processes. The yarns then are used in a single form or ply or are plied together with other yarns or filaments to produce a single but bigger yarn. One of the principal problems with spun formed yarns generally is the tendency of such yarns to unravel or fray when cut, and, depending upon the method of spinning, such yarns generally will have inherently low abrasion qualities. To try to solve this problem it has generally been known to add a low-melt fiber or filament, as a percentage, into the mass yarn bundle. Thereafter, following completion of the spinning and/or twisting process, when the yarns are processed through a heat-set range, they are generally exposed to temperatures and dwell times that melt the low-melt fibers into an adhesive that bonds the fibers and/or plies of the yarn(s) together. Other methods of solving the unraveling or fraying problem typically consist of adding adhesives to the finished yarn in a costly after-process that also tends to deter their natural surface characteristics.
One example of yarn products where the problem of unraveling and/or diminishment of surface characteristics are especially problematic is mops. Mops usually consist of one or more spun yarns containing cotton and/or other fibers of good absorption and abrasion properties, twisted as a single yarn in a Z rotation. These yarns are then grouped or plied with 2 to 32 ends of the same type yarn or other yarns of different structures or compositions and are twisted in an opposite rotation until the yarn is balanced. Such yarns generally have good absorption properties and are preferred in the janitorial field. However, by their inherent structure, these mops typically tend to unravel or lint as they are used. This shortens the usable life for the mop and tends to cause lint to be distributed on and thus diminish the finish of cleansed surfaces.
To combat this, mops made of non-woven strips have been introduced into the market. These strips are manufactured by carding and forming a fiber mass and adhering it together by adhesives or by thermal bonding. This process, however, tends to diminish or lessen the absorption properties of the mop. Further, while the use of many synthetic fibers has yielded products, such as mops, that have good abrasion properties, such products often do not have good absorption or wicking properties, particularly where the fibers are pressed or tightly linked together.
It is therefore seen that a need exists for an economical means of interlocking fibers and plies of spun yarns or filaments together to form yarns that exhibit better abrasion resistance and wicking, do not unravel as quickly, and have a longer usable life.
The present invention is directed to the formation of yarns, cordage and/or fibrous mats or bundles having enhanced strength and resistance to unraveling, and which link the properties of both spun yarns or fibers having, for example, good absorption, to other materials such as nonwoven strips having, for example, good abrasion properties, but low absorption. The resultant spun yarns, therefore, will be provided with the enhanced absorption properties of a natural or woven fiber yarn and the durable and less-linting properties of a non-woven material yarn.
Typically, the yarns are spun from a series of natural and/or synthetic fibers to form a yarn bundle or fibrous mass, and generally include core fibers wrapped or covered with sheath fibers. The yarns are fed from creels or beams along a feed path into a loom or needling apparatus or system, being pulled through the loom under tension. The yarns are each fed along a milled groove of a needle plate of the loom. Each groove has sloped sides defining a guide channel that is aligned with the feed path and a centerline of each of the yarns, and which direct the yarns downwardly and toward the center of the guide channels, so that their centerlines are aligned along the feed path as the yarns are moved through the loom.
The loom generally includes a drive plate or carrier that is reciprocally driven toward and away from the yarns passing through the grooves of the needle plate. A series of needles are arranged in spaced, parallel rows or lines of needles on the drive plate, with each of the needles typically having one or more barbs adapted to catch or pull portions of the core and sheath fibers of the yarns through the yarns as the needles are reciprocated into and out of the yarns. Each row of needles is aligned substantially directly perpendicular to the centerline of one of the yarns in the grooves so as to penetrate the yarns substantially along their centerlines and pull fibers through the yarns to substantially intermix and interlock the core and sheath fibers of the yarns. The grooves of the needle plate typically are formed with sufficient depth and slope to enable additional yarns to be stacked therein with the yarns maintained substantially parallel with their centerlines in alignment with a row of needles. The guide channels further can be arranged in substantially flat, straight configurations, or curved or arcuate configurations or construction with the needles likewise being carried by a drive plate having a similar shape or configuration so that rows of needles substantially matches that of the guide channels.
In a further embodiment, a fibrous mat can be fed along or over the yarn guides, being run parallel to the yarns for needling and attaching the yarns to a fibrous mat. Strips of material also can be attached to the yarns by positioning the strips over the yarns in the guide channels of the needle plate so that as the needles pierce the fibrous strips or webs and the yarns, fibers from the yarns, and the strips or webs are intermixed and become substantially interlocked so as to form a composite yarn/strip. As a result, composite material strips, and/or mats can be formed which incorporate different properties of one or more different types of yarns, such as, for example, combining the absorbency of a cotton or similar natural fiber yarn with the abrasive properties of a synthetic or man-made fiber, so as to create a yarn that has high absorbency and good abrasive capabilities but which does not have a tendency to lint or unravel easily, especially after repeated exposure to water and other liquids.
Various objects, features and advantages of the present invention will become apparent to those skilled in the art, upon a review of the following detailed description, when taken in conjunction with the accompanying drawings.